Known from the GFR patent description No. 1954575 is a forming press with a minimum of three starlike arranged prismatic clamping jaws, for forming tubes. The front surfaces of the clamping jaws are directed between flat inner surfaces of a press frame and they move simultaneously to a central point of a profile orifice which is formed by the clamping jaws. The surface of the clamping jaw, which lies parallel to the axis of the profile orifice, moves on the surface of an adjoining clamping jaw, reducing the profile orifice. Identical clamping jaws, fixed inside the frame, copy with their surfaces a profile orifice corresponding with the frame's inner profile. On the frame each inner flat surface clamping jaw slides on one surface. This surface of the clamping jaw adjoins with a surface limiting profile orifice, and it lies opposite the surface, and borders an adjoining clamping jaw. In the known forming press one hydraulic drive is applied, it acts on this surface of a prismatic clamping jaw, which lies opposite the surface of clamping jaw, reducing the profile orifice.
In known forming press identically shaped prismatic clamping jaws copy the profile orifice, to form a regular figure, e.g. corresponding with the press frame inside profile. One clamping jaw drive is used, directed on the jaw surface parallel to profile orifice axis, this is an inefficient solution.